Perhaps without Iago's clever plotting Othello might have had a chance to communicate with and learn to truly know Desdemona before his weaknesses were ignited. However the reality is that Iago did successfully plot Othello's downfall and is simply unavoidable with the combination of both the scheming and Othello's flaws.
Othello's love for Desdemona is so pure and new that the slightest presumption of dishonesty, planted by Iago, is manipulated and exaggerated to turn Othello's love for her into madness and murder. Act I, scene ii, 24-28, "For know, Iago, but that I love the gentle Desdemona, I would not my undousèd free condition put into circumscription and confine for the sea's worth." He describes the greatness of his love for Desdemona and how he wouldn't give it up for all the riches in the sea.
The greatness of Othello's character in the beginning leads the audience to honour him and convinces them he is strong enough to endure the evilness of his tragic fate. His greatness is partly if not solely why Desdemona fell in love with him, Act I, scene iii, 166-167 "She loved me for the dangers I had passed, and I loved her that she did pity them." She thought he was a great man and thus she fell in with him for his heroic and strong nature. Desdemona is not the only one who admires and acknowledges Othello's greatness, the Duke, Lodovico, the other soldiers and many more. It's not only his heroics and courage that make him great; he is also very respectful, honest, noble and sincere, and these qualities truly portray him to be admired and thus